213 research outputs found
Extração e exportação de macronutrientes por frutos de guaraná (Paullinia cupana var. sorbilis) no município de Maués - AM
Fruits of Guaraná (Paullinia cupana var. sorbilis) were chemically analized for N, P, K, Ca, Mg e S, with the purpose to determine the amount of macronutrient uptaked and exported by "guaraná" fruits. Four composed samples of fruits were colected from two groves fertilized and two unfertilized. Nitrogen and K was the most absorbed elements by guaraná fruits. N and P was the most exported elements. The return to the soil of fruit pulp is recomended.Foram analisados frutos de guaraná (Paullinia cupana var. sorbilis) provenientes de três propriedades do município de Maués - AM, objetivando determinar as quantidades de macronutrientes extraídas e exportadas pelos frutos de guaraná. Constituiu-se 4 amostras compostas de frutos, representando dois locais adubados e dois locais não adubados, nas três propriedades escolhidas. Constatou-se maior exigência pelo N e pelo K. Para cada produção de 100 kg de frutos (matéria seca), são aproximadamente 2,71 kg de N; 0,18 kg de P; 0,95 kg de K; 0,10 kg de Ca; 0,13 kg de Mg e 0,10 kg de S. o N e o P, são elementos mais exportados pela produção, ambos apresentando o índice de 72% de exportação, seguidos pelo S (60%), Mg (46%), K (44%) e Ca (40%). A devolução da polpa dos frutos ao guaranazal é recomendado, devido ao seu conteúdo de macronutrientes
A novel point mutation in a class IV glucose-6-phosphate dehydrogenase variant (G6PD São Paulo) and polymorphic G6PD variants in São Paulo State, Brazil
In this study, we used red cell glucose-6-phosphate dehydrogenase (G6PD) activity to screen for G6PD-deficient individuals in 373 unrelated asymptomatic adult men who were working with insecticides (organophosphorus and carbamate) in dengue prevention programs in 27 cities in São Paulo State, Brazil. Twenty-one unrelated male children suspected of having erythroenzymopathy who were attended at hospitals in São Paulo city were also studied. Fifteen of the 373 adults and 12 of the 21 children were G6PD deficient. G6PD gene mutations were investigated in these G6PD-deficient individuals by using PCR-RFLP, PCR-SSCP analysis and DNA sequencing. Twelve G6PD A-202A/376G and two G6PD Seattle844C, as well as a new variant identified as G6PD São Paulo, were detected among adults, and 11 G6PD A-202A/376G and one G6PD Seattle844C were found among children. The novel mutation c.660C > G caused the replacement of isoleucine by methionine (I220M) in a region near the dimer interface of the molecule. The conservative nature of this mutation (substitution of a nonpolar aliphatic amino acid for another one) could explain why there was no corresponding change in the loss of G6PD activity (64.5% of normal activity in both cases)
Temporal dynamics of the shrub and herbaceous layer of an area of moist grassland in Alto Paraíso de Goiás, Brazil
Este trabalho avaliou a dinâmica estrutural e fl orística de uma comunidade de espécies herbáceo-arbustivas
de uma área de campo limpo úmido em Alto Paraíso de Goiás, o primeiro inventário realizado em 2000 (T0) e o
segundo em 2007 (T1). A diversidade de Shannon entre os períodos foi comparada pelo teste-t de Hutcheson e a
similaridade fl orística, pelo índice de similaridade de Chao-Sørensen. As relações fl orísticas e a cobertura, entre os
períodos e as linhas, foram avaliadas por meio de análises de correspondência retifi cada (DCA). Foram amostradas
98 espécies, 88 no T0 e 67 no T1, sendo 31 exclusivas do T0 e 10 do T1. A diversidade fl orística na comunidade
foi elevada nos dois períodos, porém diferente entre esses (t = 7,12; p < 0,001), devido a variação no número e
cobertura das espécies. A similaridade entre os dois inventários foi alta (Chao-Sørensen ± IC = 0,841 ± 0,074). A
ordenação por DCA indicou relações entre a composição fl orística e a cobertura com o gradiente de umidade e
de matéria orgânica no solo identifi cados em T0. Houve modifi cações nas linhas em zonas sazonais, as quais se
tornaram mais semelhantes às linhas constantemente saturadas por água. Em um intervalo de sete anos o campo
limpo úmido apresentou mudanças na composição fl orística e, principalmente na estrutura devido o aumento da
cobertura de espécies perenes, cespitosas e entouceiradas, que foram favorecidas pela maior umidade no solo em
resposta à elevação da pluviosidade da região. __________________________________________________________________________________________ ABSTRACTTh is study evaluated the fl oristic and structural dynamics of a community of herbaceous-shrub species
in an area of moist grassland in Alto Paraíso de Goiás. Th e fi rst inventory was undertaken in 2000 (T0) and the
second in 2007 (T1). Shannon’s diversity between the periods was compared by Hutchesons´s t-test, and the
fl oristic similarity by the Chao-Sørensen similarity index. Floristic composition and cover, between periods and
lines, were evaluated by detrended correspondence analysis (DCA). We sampled 98 species, 88 at T0 and 67 at T1;
31 were unique to T0 and 10 to T1. Floristic diversity in the community was high in both periods, but diff erent
between them (t = 7.12, p <0.001), due to variation in species number and coverage. Similarity between the two
surveys was high (Chao-Sørensen CI = ± 0.841 ± 0.074). Th e DCA ordination indicated relationships between the
fl oristic composition and cover with a gradient of moisture and organic matter in the soil identifi ed in T0. Th ere
were changes in the lines in the seasonal zones, which became more similar in those constantly saturated with
water. During an interval of seven years the moist grassland showed changes in fl oristic composition and mainly
in structure due to increased cover of the clumped tussock perennial species, which were favored by higher soil
moisture due to high rainfall in the region
New Approaches to Clarify Antinociceptive and Anti-Inflammatory Effects of the Ethanol Extract from Vernonia condensata Leaves
The present study was aimed at evaluating the antinociceptive and anti-inflammatory effects of the ethanol extract from Vernonia condensata leaves in animal models, in order to afford a better understanding of these properties. The extract reduced the number of abdominal contortions at doses of 100 (51.00 ± 3.00), 200 (42.00 ± 2.98) and 400 mg/kg (39.00 ± 4.00). In formalin tests, a significant reduction in the licking time (p < 0.01) was observed in the first phase by 25.14 (200 mg/kg = 51.50 ± 4.44) and 31.15% (400 mg/kg = 48.00 ± 4.37). The doses of 100 (43.37 ± 5.15), 200 (34.62 ± 4.16) and 400 mg/kg (28.37 ± 3.98) inhibited (p < 0.001) the second phase. After 60 and 90 min of treatment, a dose of 400 mg/kg (10.13 ± 0.39 and 11.14 ± 1.33, respectively) increased the latency time. Doses of 200 and 400 mg/kg potentiated the sleeping time induced by diazepam, pentobarbital and meprobamate. The extracts (100, 200 and 400 mg/kg) showed anti-inflammatory effects by a decrease in paw edema. The extracts also reduced the exudate volume at the doses of 200 and 400 mg/kg. The leukocyte migration had significant effect (p < 0.001) at doses of 100, 200 and 400 mg/kg. The completion of additional experiments in the investigation of the antinociceptive and anti-inflammatory activities of V. condensata allowed a better understanding of the central and peripheral mechanisms involved
Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre
We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies.</p
Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation
The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for -ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of -ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of -ray absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift and to constrain or detect -ray halos up to intergalactic-magnetic-field strengths of at least 0.3pG. Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from -ray astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of -ray cosmology
Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project
In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory
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